using older glibc in Ubuntu 14.04 LTS for heap exploitation

I am exploring the techniques of heap overflow using unlink()technique in ubuntu 14.04 LTS.

I have studied the unlink() technique for dlemalloc algorithm for memory allocation(malloc) but i am not sure whether my system is using dlemalloc algorithm .

So,kindly suggest your ideas on :

1.how can i check whether i am usingdlemalloc?

2. if i want to use another memory allocation algorithm for ex:ptmalloc2how can i use it in my system which is already using a different algorithm(how to force the system to use the memory allocation algorithm i want ).

3.

currently system is using glibc 2.19.x(for malloc).I wanted to use glibc 2.2.4 to check the heap overflow exploit as discussed in this site

( http://ift.tt/1HahdxR ) .

How can i tell my 'c' programs to use the older version glibc2.2.4 , so that i could test heap overflow exploits.`

Thanks a lot in advance and a valuable suggestion to any of the questions would be helpful.